Carpenter s square



UNITED STATES PATENT OFFICE.

DANIEL MARTIN, OF CAMBRIDGE, MASSACHUSETTS.

CARPENTERS SQUARE.

SPECIFICATION forming part Of Letters Patent NO. 569,220, dated October 13, 1896.

Application filed January 29, 1896. Serial No. 577,221. (No model.)

To all whom it may concern:

Be it known that I, DANIEL MARTIN, residing in Cambridge, county of MiddleseX, and State of Massachusetts, have invented an Improvement in Carpenters Squares, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention relates to what is commonly known as a carpenters square, which, as now commonly constructed, consists of two rigid rules or arms extended at right angles to one another and which in practice are made of considerable length.

This invention has for its object to improve the construction of the class of squares referred to, so that one arm may be folded parallel with the other arm to enable the square.

to be carried within the usual box or toolchest with which carpenters are now commonly equipped, the movable arm of the square being locked in its open or normal position, as will be described.

Figure 1 is a front elevation of a carpenters square embodying this invention, showing the movable member or arm of the said square in its normal or open position; Fig. 2, a front elevation of the square shown in Fig. l with the movable member in its folded or closed position; Fig. 3, a plan view of the square shown in Fig. 1 Fig. 4, a front elevation with a part of the rigid member broken away to more clearly show the lock for the movable member.

The square herein shown as embodying this invention consists of the members a a, of metal or any other suitable material, extended at right angles to each other, the member a being pivoted, as at a to the finger or extension d of the member a, which finger orprojection practically forms a continuation of the member a when the latter is in its open position. (Shown in Fig. 1.) The member a is adapted to be folded on its pivot a from the position shown in Fig. 1 to its closed position, substantially parallel with the member a, as shown in Fig. 2, and in order to hold rigid the member a in its open position (shown in Fig. 1) while the square is being used a looking device is provided for the movable member a.

In the present instance the movable member ais provided at its upper surface With a recess or notch 12, (see Fig.4,) forming a shoulder 1), with which engages a finger or projection 21 on the under side of a lever b pivoted, as at 5 in a suitable cavity or slot 12 made in the upper end of the member a, the pivot 19 being extended through the side walls of the said slot. The lever b is pivoted in its slot so that its upper surface preferably is flush with the upper surface of the member a, as clearly shown in Fig. 4, and the said pawl is maintained in engagement with the locking shoulder or projection 19 on the member a by means of a suitable spring, herein shown as a bent fiat spring b secured to the under side of the lever 6 preferably by extending the end of the spring into a slit in the under surface of the said lever; but instead of the particular form of spring herein shown I may employ any other desired or suitable form.

hen it is desired to disengage the locking-lever b from the shoulder b, the rear end of the said lever may be thrust down into the slot Z2 so as to lift its front end up out of the said slot and thereby disengage the finger or pawl from the shoulder 12, but to facilitate this disengagement of the locking-lever with the member a I prefer to provide the said lever with a fin ger-piece b extended through a slot I) in one wall of the cavity or slot 12 By reference to Fig. 1 it will be seen that the finger-piece b may be readily drawn down in its slot, which movement will turn the lever b on its pivot and disengage the pawl or finger b from the shoulder 12, and the said pawl b will be carried up above the member a sufficiently far to enable the member a to be turned on its pivot a and be folded into its closed position. (Shown in Fig. 2.) In its closed position the square may be carried in the pocket or preferably in a carpenters tool-chest, or, if desired, it may be conveniently carried in the hand, and when it is desired to use the tool or instrument the member a may be turned outward away from the member a until the shoulder 12 is carried by the engaging-pawl b and the member a is at such time in its normal or open position,with the pawl b in engagement with the shoulder 1).

I claim lever b and a finger-piece secured to the said lever and extended through a slot in the side wall of the slot b substantially as described.

In testimony whereof I have signed my I 5 name to this specification in the presence of two subscribing witnesses.

DANIEL MARTIN. \Vitnesses:

JAs. H. CHURCHILL, J. MURPHY. 

